Engine Performance problem
1989 Volvo 760 4 cyl Two Wheel Drive Automatic 190000 miles
I have a 1989 Volvo 760 turbo intercooled wagon that when it idles it kind of surges and when I rev it and let it go back to idle it wants to die. I have checked for vacume leaks and checked the timing. As well as changed the thermal-meter thing on the side of the head. I am not sure but I have no engine light but it seems to run great when it's cold and when it starts to warm up this problem happens.
I would first get a scan done to check for any unresolved fault codes, check for any vacuum leaks as well, the idle speed is controlled by the ECU you can check and adjust the base idle, see pic & text for details, start here.